Previously we have documented increasing rates of neuropsychological (NP) impairment at each successive stage of HIV infection, and have reported preliminary evidence that such impairment is associated with lowered employment rates and problems with vocational functioning. We propose to extend these findings by assessing cross-sectional and longitudinal relationships between NP impairments and important aspects of everyday functioning, including vocational functioning, automobile driving, and more routine activities required for independent living. The findings from this study should enhance our understanding of both the functional impacts of HIIV-associated NP impairment and the NP abilities that are associated with successful performance of everyday activities. Additionally, it will provide information regarding novel outcome methodologies that may be important in the evaluation of pharmacological interventions with cognitively impaired, HIV+ individuals. We will recruit subjects from the NIMH-funded HIV Neurobehavioral Research Center, thus providing the current study with extensive, longitudinal NP, neurological, and medical data at no cost. All HIV+ subjects (and significant others, when available) will provide detailed ratings regarding the subjects' everyday functioning in all three domains; also we will obtain driving records and objective laboratory assessments utilizing standardized work samples, a driving simulator, and a direct assessment of activities of daily living. Longitudinally, subjects who (1) change neurocognitive diagnostic classification (NP Normal, subsyndromic NP impairment, Minor Cognitive/Motor Disorder, and HIV-Associated Dementia), and (2) exhibit a clinically significant improvement or worsening in NP status, will receive a repeat functional assessment. Control groups for the longitudinal comparisons will consist of NP stable subjects who are individually matched with transitioning subjects on baseline functional levels. Compared to NP Normal subjects, it is predicted that at baseline NP impaired subjects: (a) will have higher unemployment rates, will show more "downward drift" in the kinds of jobs they are performing, and will perform less well on standardized work samples, (b) will have increased rates of automobile accidents and perform worse on the driving simulator, and will have increased difficulties with activities of daily living (for those meeting diagnostic criteria for syndromic NP impairment). Performance on the laboratory measures are expected to be associated with both subjects' and significant others' reports of the subject's functioning. Longitudinally, we expect to see concordance between changes in NP status and changes in the laboratory assessments and subjective reports of everyday functioning, further clarifying the cause-effect nature of the cross- sectional relationships.